private async Task <UserRecord> GetUserAsync(UserQuery query, CancellationToken cancellationToken) { var response = await this.PostAndDeserializeAsync <GetAccountInfoResponse>( "accounts:lookup", query.Build(), cancellationToken).ConfigureAwait(false); if (response == null || response.Users == null || response.Users.Count == 0) { throw new FirebaseException($"Failed to get user with {query.Description}"); } return(new UserRecord(response.Users[0])); }